Sonneratia Alba Research Articles

Diminishing mangrove forest structures in Davao City, Philippines

The decline of mangrove coverage across the Philippines to 50% of its original coverage in present years has, led to significant reductions of ecological functions to fisheries and benefits to man. The mangrove forest in Davao City was assessed for its taxonomic list, Importance Value Index, abundance and distribution of mangrove regenerations, forest structure, and species diversity status. The study was conducted in Barangay Bunawan, Lasang, Panacan, Matina Aplaya, 76-A, and Bago Aplaya. All data were gathered by establishing sampling plots (10m x 10m) using the modified transect-plot method. Overall, a total of 34 mangrove species were listed, of which 21 were identified as true mangroves and 13 as mangrove associates. The 21 mangrove species were very low in species richness (54%). Importance Value Index showed that Avicennia marina, Rhizophora apiculata, and Sonneratia alba, respectively, as dominant mangrove species. The mangrove regenerations were in poor condition (<0.50) while relative abundances of growth stages consisted of mature stands at 46.04%, saplings with 27.78%, and seedlings with 26.18%. General diversity indices obtained a low value on the Shannon-Wiener diversity index (H'=1.42) and an average value on the species evenness index (E=0.61), all indicating stressful and unstable mangrove forests. Thus, the mangrove forest ecosystem has imbalances and eventually, only certain species would survive.

Structure and composition of rehabilitated mangrove in Lubuk Kertang Village, North Sumatra, Indonesia

Mangroves are generally distributed in tidal zones along tropical and subtropical coasts and are known as woody halophytes. Mangroves are one of the most productive and efficient long-term natural carbon sinks. Deforestation and mangrove degradation produced substantial carbon emissions that account for the majority and salt marshes emissions. Mangroves play an important role in protecting against storms and sea level rise, preventing coastline erosion, regulating coastal water quality, providing habitat for commercial interests. This study was conducted to measure the diversity, structure and composition of forests in the rehabilitation of abandoned pond mangrove forests in Lubuk Kertang Village, West Brandan District, Langkat Regency, North Sumatra. The method used was to conduct a census in a 1.6 ha restoration forest by measuring the overall diameter, height and species found. Fourteen species were found, namely Aegiceras corniculatum, Avicennia marina, Acrostichum aureum, Bruguiera gymnorrhiza, Ceriops tags, Exoecaria agallocha, Finlaysonia maritimea, Nypa fruticans Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Sonneratia alba, Scyphiphora hydrophyllacea, Sesuvium portulacastrum.

Effect of soaking mangrove fruit (Sonneratia alba) with lime water on crude protein, crude fiber, and nitrogen free extract content as a ruminant feed

The mangrove plant is among the strees found growing in the seaside zone, one part by the mangrove plant that Could be utilized as livestock feed for ruminants is mangrove fruit. Mangrove fruit is usually rarely used so it only rots and pollutes the coast. The aim in thus study is to see effects by mangrove fruit tannin reduction with lime water on crude protein, crude fiber, and NFE content. This study used 4x3 Faktorial pattern group randominsation plan using 2 seplicates. The first factor is the concentration by lime water with 4 levels, that is T1 (1% lime water), T2 (3% lime water), T3 (5% lime water), T4 (7% lime water). The second factor is different soaking times with 3 times, namely 10 minutes, 20 minutes, and 30 minutes. The conclusion of the research on soaking mangrove fruit with lime water gives a very significantly different effect on crude protein, crude fibre, and NFE content. The highest crude protein content is in the A1B1 treatment with a grade of 8.1%, the best crude fibre was in the A3B3 treatment with a value of 24.91%, and NFE was in the A1B1 treatment with a value of 58.07%.

Pemetaan Sebaran Jenis Mangrove Menggunakan Citra Drone dengan Metode Object-Based Image Analysis (OBIA) di Sungai Pisang, Kecamatan Bungus Teluk Kabung, Kota Padang

This research has purpose to find out what types of mangroves and factors affect the distribution of mangroves in Sungai Pisang, Bungus Teluk Kabung District, Padang City. The research method used is quantitative research. The data used is primary data such as drone imagery. The results of this research produced seven types of mangroves and factors the distribution of mangrove types. The types of mangroves found were Rizhophora apiculate, Oncomsperma tigillarium, Ceriops tagal, Bruguiera gymnorhiza, Hibiscus tiliaceus, Acrostichum aureum linn, Sonneratia alba. Meanwhile, there are three factors that influence the distribution of mangroves, namely Substrate, Salinity and Soil Texture. The dominant substrates are muddy and sandy substrates, the lowest salinity is 12ppt and the highest is 30ppt, while the dominant soil textures are clay, clay and sandy.

Analysis of Mangrove Leaf Litter Decomposition Rate in Mangrove Ecosystem of Muara Pagatan, South Kalimantan

Mangroves are the dominant ecosystem in coastal areas and estuaries and one of the most productive ecosystems in the world. Mangroves are an essential component in a complex food chain and have the potential for the life of various marine and terrestrial biotas, microorganisms, and macroorganisms. The decomposition of mangrove leaf litter by fungal bacteria produces nutrient source that is beneficial for fish, shrimps, and crabs. This study discusses the production and decomposition rate of mangrove leaf litter in the mangrove ecosystem of Muara Pagatan, South Kalimantan. With transect and litter trap methods, litter production during the observation ranged from 218.51 - 858.28 g/m2/45day. Of the four types of mangroves found, the highest litter production was found in Rhizophora mucronata mangrove species at 858.28 g/m2/45day, followed by Bruguiera gymnorrhiza species at 268.52 g/m2/45day, and the lowest litter production was Avicennia marina mangrove species at 222.9 g/m2/45day and Sonneratia alba at 218.51 g/m2/45day. The remaining dry weight during observation ranged from 1.06 g - 2.46 g. In sum, the highest litter productivition and decomposition rate was found in Rhizophora species and litter was not completely decomposed after 45 days.

Blue Carbon Potential of Mangrove Ecosystem on the Coast of Negeri Waai, Central Maluku Regency

The mangrove ecosystem contributes to climate change mitigation by absorbing carbon dioxide gas. The shoreline of Negeri Waai, Central Maluku Regency (CMR), becomes one of Indonesia's promising mangrove ecosystem habitats for carbon absorption. Therefore, this research aimed to assess the blue carbon potential of mangroves on the coast of Negeri Waai, CMR. This research collected data using the quadrant transect method (10 x 10 m) and placed randomly in 65 quadrants. The analysis of blue carbon potential used an allometric approach to above and below-ground biomass (AGB and BGB). The results showed that the total blue carbon mangrove stock on the coast of Negeri Waai was 73.22 ton C/ha, consisting of 49.44 tons C/ha above-ground carbon (AGC) and 23.78 tons C/ha below-ground carbon (BGC). Sonneratia alba contributed the most extensive carbon stock, namely 70.69 ton C/ha, consisting of 47.53 tons C/ha AGC and 23.16 tons C/ha BGC. This result was relatively low compared to the global average of blue carbon in mangroves, 134 ton C/ha. Based on this result, efforts were needed to restore the mangrove ecosystem, increase the potential for carbon absorption, and mitigate climate change.

Analysis of Mangrove Density using NDVI and Macrobenthos Diversity in Ampekale Tourism Village South Sulawesi, Indonesia

The mangrove ecosystem faces significant challenges, as its quality and quantity are threatened with decline. This study aimed to analyze the mangrove density and macrobenthos diversity in the Ampekale Ecotourism Village, Indonesia. This research utilizes remote sensing image analysis through the Normalized Difference Vegetation Index (NDVI) method. Complementary ground-check surveys were conducted to ascertain the density and diversity of mangrove and macrobenthos species. The overall mangrove density in the Ampekale area was relatively high, with some areas displaying moderate density. The sequence of mangrove species, from most common to least common, includes Rhizophora mucronata, Avicennia marina, Avicennia alba, Rhizophora apiculata, Sonneratia alba, Bruguiera gymnorhiza, and Acanthus ilicifolius. The most prevalent macrobenthos belong to the Crustacea class, such as Uca sp., Sesarma, Metaplax sp., and Scylla serrata. Moreover, the most diverse macrobenthos belong to the Gastropods class. The distribution of this biodiversity depends on their location (coastal or inland), tidal fluctuations, and river estuaries. Mangrove ecosystems situated in estuaries with high densities exhibited elevated macrobenthos abundance. This correlation suggests that areas characterized by dense mangroves also harbor stable ecosystem conditions with abundant macrobenthos. In contrast, ecosystems featuring lower biodiversity demonstrated reduced stability. These findings contribute valuable insights into the conservation and sustainability of mangrove ecosystems. Keywords: ecotourism, macrobenthos, mangrove density, mangrove ecosystem, NDVI

Identification of the pest outbreak in the coastal mangrove ecosystem of Mahakam Delta, East Kalimantan, Indonesia

Abstract. Harmonis, Haqiqi MT, Fahroni MFA, Jefry, Gunawan S, Sekedang MA, Rahmat D, Azhar NF, Putra MOPS, Kusuma FD, Hapsari MT, Muhammad FA, Diana R, Sudarmadji T, Amirta R, Ariyanto, Saud OR, Sofyan FPM, Fajriansyah, Asngari AMS, Bulo YS, Salman I, Rizaldi R, Lubis KM. 2024. Identification of the pest outbreak in the coastal mangrove ecosystem of Mahakam Delta, East Kalimantan, Indonesia. Biodiversitas 25: 829-835. Mangrove ecosystems are considered the most essential areas in the wetland since they sequester carbon more efficiently than terrestrial ecosystems. Thus, they have received significant attention as a nature-based solution to achieve the Naturally Determined Contributions in the commitment to global climate change mitigation. Currently, the degradation of mangroves has been linked to serious threats, including pest outbreaks. Our primary objective was to assess the pest outbreaks that occurred in the coastal mangroves of the Mahakam Delta, Indonesia. This study was conducted in two areas in Tanjung (R1 and R2) and one area in Pulau (R3). A total of 19 observation plots with a size of 10 × 10 m2 were made. The water quality was further measured to identify the natural conditions affecting the outbreaks. In the present study, it was found that significant disturbance of the mangrove plants occurred due to invasions by Amphibalanus amphitrite Darwin, 1854 and Sphaeroma terebrans Spence Bate, 1866. The dangerous attack from S. terebrans has only been found at the R1 site, where we found environmental conditions such as high dissolved oxygen (DO), high total dissolved solids (TDS), and high salinity. In this area, it could affect the death of adult Avicennia alba Blume and Sonneratia alba Sm. The results obtained from this study are expected to provide preliminary data to design the best management practices in order to enhance the effectiveness of the mangrove rehabilitation strategy in the Mahakam Delta.

Ethnobotanical and ecological study of medicinal plants of mangroves in Siak District, Riau Province, Indonesia

The mangrove forest in Kayu Ara Permai Village, Sungai Apit, Siak Regency, Riau Province, Indonesia, is a mangrove forest managed by the local community as the "Historic River" Mangrove Ecotourism Area. Mangrove forests have become a tourist attraction for many local and national tourists. The purpose of this study was to identify plants that have potential as medicinal plants in mangrove ecotourism areas of "Sungai Bersejarah" Kayu Ara Permai Village, Sungai Apit, Siak Regency, Riau Province. This study used a survey method in mangrove forests to conduct an inventory of the medicinal plants scattered throughout the area. Observations were made using a combination of the path and plot methods. The investigation was carried out by cross-checking the traditional use of medicinal plants by the surrounding community with the scientific literature. The results showed 7 species of medicinal plants from 5 different families, namely Avicennia alba, Rhizophora apiculate, Bruguiera parviflora, Bruguiera gymnorrhiza, Xylocarpus granatum, Sonneratia alba, and Acrostichum aureum. Mangrove density levels were in the sparse category (1,000 trees/ha) and had low diversity levels, with two dominant species, Rhizophora apiculata and Xylocarpus granatum.

Inventory of mangrove species diversity in Ruar village, Biak Numor Regency, Papua Province

Efforts to preserve mangrove forests through species diversity inventory are important input data in mangrove forest management. The purpose of this research is to investigate the potential and diversity of mangrove forest species in Ruar village, Biak Numfor Regency, Papua Province. Inventory of mangrove species using the grid line method which is laid systematically. The distance between the lanes is determined to be 200 meters and plots are placed to the left and right of the lanes, making up as many as six lanes/transects. The results of this study, there are 5 species, namely Sonneratia alba, Rhyzophora stylosa, Rhyzophora apiculata Bl, Bruguiera gymnorhyza (L) Lamk, Ceriops tagal (Perr). C.B.Rob. On tree growth rates were dominated by Rhyzophora apiculate Bl (INP 152.73%), sapling and seedling rates dominated by Bruguiera gymnoriza (L) Lamk (INP 137.85% and INP 128.46%). Species diversity index according to tree growth rate (0.874), sapling rate (0.678) and seedling rate (0.667). According to Shannon-Wienner criterion (H’ <1), the species diversity index in the mangrove forest of Ruar Village, Biak Numfor Regency is low. Species enrichment planting activities are needed in maintaining and increasing the diversity of mangrove species to control environmental disturbances.

Identification of species composing the Bagik Batu mangrove ecosystem, Jerowaru, Indonesia

Preserving mangrove ecosystems is an important part of several global warming mitigation efforts. The latest information about the existence of mangrove ecosystems is important information for evaluating the current condition of mangrove forests. This research aims to examine the species that make up the Bagik Batu mangrove ecosystem in Jerowaru, Indonesia. Information related to the condition of the Bagik Batu mangrove ecosystem can be initial information for policy decisions by policymakers in formulating policies related to global warming mitigation. This research is descriptive (Survey). Area samples were taken using purposive sampling and the plot sampling method (random), and then many mangrove individuals were identified based on their morphological characteristics, starting from leaves, flowers, fruit, seeds, stems, and roots. In addition, the data used in this study are data on the number of individuals per species and environmental parameter data such as pH, temperature, salinity, and substrate type. The research results show that the Bagik Batu mangrove ecosystem consists of several types of mangrove species, namely Avicennia alba, Calotropis gigantea, Lumnitzera racemosa, Rhizophora apiculata, Rhizophora stylosa, and Sonneratia alba.

Species composition and mangrove forest structure in Buano Island, Moluccas

Mangrove forests are protected areas that play an important role for coastal communities on small islands. This study aims to convey data and information about the structure and composition of mangrove species on Buano Island. The Importance Value Index (INP) obtained from vegetation analysis is used as an indicator to describe the composition and structure of mangrove forests. The plot-assisted path method is used in vegetation analysis. 9 illustrative paths with a width of 200 m were created which were divided into 9 segments, there were 54 plots to obtain data and types of mangroves. The research results showed that there were 12 types of mangrove trees and forest regeneration (Heritiera littoralis, Rhizopora Mucronata, Rhizopora stylosa, Rhizopora apiculata, Ceriops Tagal, Sonneratia alba, Bruguiera gymnorrhiza, Lumnitzera racemose, Aegiceras corniculatum, Deriss trifoliata, Nypa fruticans, Xylocarpus granatum). The dominant species is R. mucronata. The vegetation structure at both locations also has a similar pattern the same, where the vertical structure has 2 layers/stratum of trees and both are dominated by trees with a height of 6-10 meters. Meanwhile, for the horizontal structure, the distribution of diameter classes at both locations is even, marked by a graph that forms an L curve.

Analysis of Mangrove Vegetation in Lohgung Village, Brondong Sub-District, Lamongan Regency

Mangroves are vegetation that grows in muddy areas in tidal areas, coastal areas , and river estuaries. Mangrove forests have an ecological function as providing food for marine biota, preventing tidal waves and tsunamis, preventing sea water intrusion, preventing coastal erosion and absorbing waste. This research aims to determine the species and Importance Value Index in the mangrove area of Lohgung Village, Brondong District, Lamongan Regency, which included Relative Density (KR), Relative Frequency (FR), and Relative Dominance (DR). This research was carried out in Lohgung Village, Brondong District, Lamongan Regency from May to June 2023. The method used in sampling used a combination of the line method (line transect) and the plot line method (quadrant transect). The results showed that the types of vegetation found in Lohgung Village, Brondong District, Lamongan Regency consisted of 8 species from 5 different families, namely Sonneratia alba, Rhizophora apiculata, Rhizophora mucronata, Bruguiera gymnorrhiza, Ceriops tagal, Lumnitzera racemosa, Excoecaria agallocha L., and Xylocarpus moluccensis. The results of calculating the values of Density (K), Relative Density (KR), Frequency (F), Relative Frequency (FR), Dominance (D), Relative Dominance (DR), and Importance Value Index (IVI) in all categories, trees, saplings and seedlings showed that the highest value that dominated was Rhizophora mucronata with an IVI value of 102.08%, 68.73% for saplings and 75.40% for seedlings.

Analysis of active compounds and bioactivity of leaves extracts of Sonneratia species

AbstractThe present study focused on the quantitative determination of active compounds, antioxidant and antibacterial activities of leaf extracts of different Sonneratia species. The tested species including Sonneratia alba (SA), Sonneratia caseolaris (SC), and Sonneratia ovata Backer (SO) were collected from Can Gio Mangrove Forest, Vietnam. The methanol extract of SA leaves was found to contain the highest content of total flavonoids, total phenolics and gallic acid (4344.16 ± 51.78 μg/g dry mass). The highest luteolin‐7‐O‐glucoside and luteolin amounts (5963.28 ± 59.77 and 234.33 ± 10.41 μg/g dry mass, respectively) were found in the methanol extract of SC leaves according to HPLC‐DAD analysis. The methanol extracts of all three species exhibited strong DPPH radical scavenging activity while the ethanol extracts provided strong antibacterial activity against Staphylococcus aureus, Salmonella typhimurium, and Escherichia coli. By fractionating the extracts over a SiO2 column using CHCl3: EA: MeOH gradients, the fractions containing high purity luteolin and luteolin‐7‐glucoside from SC and high purity luteolin from SO were collected. Moreover, all fractions demonstrated significant DPPH free radical scavenging ability but the fraction enriched in gallic acid showed the highest activity. These findings show that SA is a promising source of gallic acid while SC can be potentially used for the extraction and isolation of luteolin‐7‐glucoside.

Genomic evidence for rediploidization and adaptive evolution following the whole-genome triplication

Whole-genome duplication (WGD), or polyploidy, events are widespread and significant in the evolutionary history of angiosperms. However, empirical evidence for rediploidization, the major process where polyploids give rise to diploid descendants, is still lacking at the genomic level. Here we present chromosome-scale genomes of the mangrove tree Sonneratia alba and the related inland plant Lagerstroemia speciosa. Their common ancestor has experienced a whole-genome triplication (WGT) approximately 64 million years ago coinciding with a period of dramatic global climate change. Sonneratia, adapting mangrove habitats, experienced extensive chromosome rearrangements post-WGT. We observe the WGT retentions display sequence and expression divergence, suggesting potential neo- and sub-functionalization. Strong selection acting on three-copy retentions indicates adaptive value in response to new environments. To elucidate the role of ploidy changes in genome evolution, we improve a model of the polyploidization–rediploidization process based on genomic evidence, contributing to the understanding of adaptive evolution during climate change.

Preliminary Study on Floral Distribution, Abundance and Diversity of Mangroves in Vankalai, North-west Coast of Sri Lanka

Sri Lanka harbors a remarkable amount of mangrove habitats. Northern Province shares about 16% of the total mangrove extent of the country. Vankalai consists of several ecosystems which range from arid-zone thorn scrubland, arid-zone pastures and maritime grasslands, sand dunes, mangroves, salt marshes, lagoons, tidal flats, sea-grass beds and shallow marine areas. Due to the integrated nature of shallow wetland and terrestrial coastal habitats, this sanctuary is highly productive, supporting high ecosystem and species diversity. The research was aimed to identify the distribution, abundance and diversity of mangroves in Vankalai of the Northern Province, Sri Lanka. Ten 25m wide belt transects with 10m intervals were randomly arranged in the small patch of mangrove vegetation perpendicular to the 350m of shoreline across the water-land gradient. Each transect was divided into five 5mx5m subplots for convenience of sampling. True mangrove species in each transect were identified and counted. The quantitative data has been used to compute the Shannon diversity index (H), Simpson Index (D) and Shannon Evenness (E), which were used to compare the diversity of the study sites. Ten different mangrove species including Avicennia marina (n=115), Avicennia officinalis (n=73), Rhizophora apiculate (n=33), Rhizophora mucronata (n=102), Sonneratia alba (n=3), Pemphis acidula (n=4), Excoecaria agallocha (n=40), Lumnitzera racemose (n=91), Bruguiera cylindrical (n=97), Ceriops tagal (n=31) were identified and they were belonging to five families; Avicenniaceae (n=2), Rhizophoraceae (n=5), Lythraceae (n=1), Euphorbiaceae (n=1) and Combretaceae (n=1). Further, based on the IUCN status, two mangrove species (Sonneratia alba and Bruguiera cylindrical) were identified as endangered species. The highest Shannon diversity index (H=2.21) and the lowest Simpson index value (D=0.14) were observed in the transects of point 1 due to minimal disturbances. The least Shannon diversity index and evenness were recorded in the point 5 as 1.65 and 0.85 respectively at the point 5 since fishing and tourism activities take place in the proximity of this place. The Shannon diversity index varied at the points of 1 (H=2.21)&gt;2 (H=2.10)&gt;3 (H=1.89)&gt;4 (H=1.84)&gt;5 (H=1.65) whereas Simpson index value were varied at the points of 1 (D=0.14)&lt;2 (D=0.17)&lt;3,4 (D=0.18)&lt;5 (D=0.19) respectively. Pollution and human interaction would have degraded the environmental quality of the mangrove habitats. Based on the observations it was found that the extent of disturbances was minimum at the points of 1 and 2 whereas anthropogenic influence was increased at the points of 3&lt;4&lt;5 respectively. Further, use of mangrove poles and sticks to build fish baits and fishing rods by the anglers could possibly destroy these small patches of mangroves. Hence, actions should be taken for conservation of existing patch and replenishment of new mangroves. &#x0D; Keywords: Mangroves, Diversity, Shannon Diversity Index (H), Simpson Index (D) and Shannon Evenness (E)

Karakteristik Polen pada Spesies Mangrove di Kawasan Hutan Mangrove Batu Lumbang, Denpasar, Bali

The diversity of mangrove species in an area can be observed through morphological structure, anatomy, as well as palynology. Palynology is a study of pollen that frequently used as a reference to support data in identifying mangrove species. Mangrove areas in Bali have patchy distribution, one of which can be found in the Batu Lumbang area. Batu Lumbang is a mangrove area that is part of the Ngurah Rai Forest Park. Observation of the micromorphological characteristics of pollen in the Batu Lumbang mangrove forest area was carried out through the acetolysis method with modification. Eleven mangrove species were sampled, comprised of Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorhiza, Ceriops tagal, Exoecaria agallocha, Lumnitzera racemosa, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, Sonneratia caseolaris, and Xylocarpus granatum. The results of observations on pollen from eleven species of mangroves show similarities of pollennits, monads. In addition, other pollen characters such as aperture type, pollen shape, and pollen size categories found vary among the samples observed. These characters can also group several species that have the same family or genus. In turns, these can be used as diagnostic character to distinguish one species with another.

Floristic composition of mangrove community in Ngurah Rai Forest Park and Nusa Lembongan, Bali, Indonesia

Abstract. Wijaya IMS, Sugiana IP, Astarini IA, Ginantra IK, Rahim KAA. 2024. Floristic composition of mangrove community in Ngurah Rai Forest Park and Nusa Lembongan, Bali - Indonesia. Biodiversitas 25: 300-309. The floristic composition of mangroves can be influenced by various factors, one of which is the size of the island. In Bali, Ngurah Rai Forest Park is one of the mangrove areas in the mainland of Bali, while Nusa Lembongan on the southeastern mainland represents the mangrove on the small island. This research aimed to study the floristic composition of the mangrove species in Ngurah Rai Forest Park and Nusa Lembongan based on the species diversity and the structure of mangrove community. Based on the explorative method, both locations have 20 true mangrove species cumulatively, with 18 species in Ngurah Rai Forest Park and 15 species in Nusa Lembongan. The mangrove community structure is majorly composed by Sonneratia alba and Rhizophora (R. apiculata, R. mucronata, and R. stylosa) in trees, saplings, and seedlings. Sonneratia alba has more impact in relative dominance, while the Rhizophora has more impact in relative density. Based on the Shannon-Wiener Index of Diversity, the mangrove community status is Moderate in both locations in all growth forms (trees, saplings, and seedlings). The Index of Dominance and Index of Evenness indicates the mangrove community is in stable condition with no extremely dominated species and fairly even species distribution. The mangrove condition is categorized as Good with Dense Trees based on the Decree of the Minister of Environment number 201 of 2004.

High-throughput analysis using 16S rRNA sequencing of bacterial communities associated in selected mangrove species from Bayug Island, Iligan City, Philippines

Abstract. Siblos SKV, Tabugo SR. 2023. High-throughput analysis using 16S rRNA sequencing of bacterial communities associated in selected mangrove species from Bayug Island, Iligan City, Philippines. Biodiversitas 25: 53-61. Mangrove ecosystems are recognized globally as highly productive ecosystems, that play a crucial role in carbon sequestration, erosion control, water purification, and as essential breeding grounds for diverse aquatic life. They also offer specialized ecological niches, accommodating a diverse range of organisms, including bacterial communities. This study aimed to investigate bacterial communities of Bayug Island in Iligan City, Philippines, inhabiting six mangrove species, namely Rhizophora stylosa Griffith, Rhizophora apiculata Blume, Rhizophora mucronata Lam., Sonneratia alba Sm., Ceriops tagal (Perr.) C.B.Rob., and Nypa fruticans Wurmb and their possible functions within the mangrove forests. Genomic DNA was extracted from the six pooled soil samples, and the V3-V4 region of the 16S rRNA gene was sequenced using the Illumina MiSeq platform. Six amplicon libraries, corresponding to the mangrove species were analyzed with Parallel Meta Suite software, yielding 173,270 amplicon sequence variants (ASVs) after quality control. The study identified the top five most abundant ASVs in the mangrove rhizosphere, linked to the genera Vibrio, Stenotrophomonas, Serratia, Pseudoalteromonas, and Achromobacter. Among the mangrove species, S. alba exhibited higher alpha diversity according to the Shannon index. PICRUSt analysis revealed that microorganisms are involved in biodegradation, xenobiotic metabolism, and other metabolic processes within the mangroves. These bacteria could find applications in environmental cleanup, bioremediation, waste treatment, and soil health improvement. This result contributes to the ongoing ecological restoration of mangrove forests at the research site.

Carbon stock estimation of Sonneratia alba in mangrove restoration area in Pasar Rawa, Langkat North Sumatera

Mangrove forests must be protected because they are an important ecosystem for climate mitigation. Mangrove forests are one of the “blue carbon” ecosystems capable of absorbing significantly more carbon than terrestrial forests. Mangrove restoration is being carried out in various regions as part of an effort to rehabilitate damaged ecosystems, one of which being Pasar Rawa Village in Langkat Regency. Sonneratia alba is a native plant that is employed in restoration activities. The purpose of this study is to investigate carbon stock in the S. alba monoculture restoration area in Pasar Rawa Village, Langkat Regency, North Sumatra Province. Purposive sampling was employed in this study, with plots distributed evenly around the research area. Carbon stock estimation is performed non-destructively by estimating carbon estimates based on diameter at breast height (DBH) and total height of trees. According to the research findings, the total carbon stored in the Sonneratia alba restoration area is quite low, at 60.89 ton.ha−1. S. alba produced 192.13 ton.ha−1 of absorbed carbon with CO2 absorption of 19212.84 g/m2 and so was classified as low.